Titanium complexes have been investigated for their antitumor activity. Many factors including isome — Inorganic Chemistry Chemistry Question

A reaction of 2 equivalents of 2-tert-butylphenol, 2 equivalents of formaldehyde, and N,N'-dimethylethylene^-1,2-diamine under acidic conditions at 75 °C affords three major products with the same chemical formula of C₂₆H₄₀N₂O₂, as shown in the equation below. Draw the structure of each product.

If 2,4-di-tert-butylphenol is used as a substrate instead of 2-tert-butylphenol using the same stoichiometry as that in 7.1, only one product X was obtained. Draw the structure of X.

A reaction between X from 7.2 and Ti(OiPr)₄ [ iPr = isopropyl] in diethyl ether under an inert atmosphere resulted in the six-coordinate Ti complex Y, as a yellow crystalline solid and isopropanol at room temperature.
UV^-VIS spectra of X, Ti(OiPr)₄, and Y reveal that only the product Y has an absorption at  = 370 nm. By varying the volumes of X and Ti(OiPr)₄, each with the concentration of 0.50 mol dm^-3, and using benzene as the solvent, the absorbance data at  = 370 nm are given below:

Volume of X (cm₃) | Volume of Ti(OiPr)₄ (cm₃) | Volume of benzene (cm₃) | Absorbance
0 | 1.20 | 1.80 | 0.05
0.20 | 1.00 | 1.80 | 0.25
0.30 | 0.90 | 1.80 | 0.38
0.50 | 0.70 | 1.80 | 0.59
0.78 | 0.42 | 1.80 | 0.48
0.90 | 0.30 | 1.80 | 0.38
1.10 | 0.10 | 1.80 | 0.17
1.20 | 0 | 1.80 | 0.02

Fill in appropriate values in the table provided below.
mol of X / (mol of X + mol of Ti(OiPr)₄) | | | | | | | |
Absorbance | 0.05 | 0.25 | 0.38 | 0.59 | 0.48 | 0.38 | 0.17 | 0.02

Next figure: Plot a graph showing a relationship between and absorbance in the space provided below.
The value of which maximizes the amount of the product Y represents the stoichiometry of X in the chemical formula of Y. Based on the graph above, show what is the molar ratio Ti : X in the complex Y.

The titanium complex Y is six-coordinated. The IR spectrum of Y does not contain a broad absorption band in the range of 3200 – 3600 cm^-1. Y exists as three diastereomers. Ignoring stereochemistry at N atoms, draw clearly the structures of all three diastereomers.
Note that you do not need to draw the complete structure of the ligand. Only identify donor atoms that involve in coordination with titanium and the ligand framework between the donor atoms can be drawn as follows:
For example: can be drawn as:
If you did not get a structure of X from 7.2, use the following ligand symbol to represent X (A and Z are donor atoms):

Under certain conditions, the reaction shown in equation 1 affords only one diastereomer of Y. Given that structures of Y are "fixed" (no intramolecular movement), the ¹H NMR spectrum of Y in CDCl₃ shows four singlet resonances at  1.25, 1.30, 1.66, and 1.72 corresponding to the tert-butyl groups. Draw a structure of the only possible diastereomer of Y.
(You do not need to draw the complete structure of the ligand. Only identify donor atoms that involve in coordination and the ligand framework between the donor atoms can be drawn as shown in 7.4).